WASHINGTON >> President Joe Biden and his top advisers have tried for months to press forward amid a seemingly endless drumbeat of dispiriting news: rising inflation, high gas prices, a crumbling agenda, a dangerously slowing economy and a plummeting approval rating, even among Democrats.

But Biden has finally caught a series of breaks. Gas prices, which peaked above $5 a gallon, have fallen every day for more than six weeks and are now closer to $4. After a yearlong debate, Democrats and Republicans in Congress passed legislation this past week to invest $280 billion in areas like semiconductor manufacturing and scientific research to bolster competition with China.

And in a surprise turnabout, Sen. Joe Manchin, D-W.Va., who had single-handedly held up Biden’s boldest proposals, agreed to a deal that puts the president in a position to make good on promises to lower drug prices, confront climate change and make corporations pay higher taxes.

“The work of the government can be slow and frustrating and sometimes even infuriating,” Biden said at the White House on Thursday, reflecting the impatience and anger among his allies and the weariness of his own staff. “Then... pays off. History is made. Lives are changed.”

Even for a president who has become used to the highs and lows of governing, it was a moment to feel whipsawed. Since taking office 18 months ago, Biden has celebrated successes like passage of the $1.9 trillion stimulus bill and slogged through crises like the chaotic withdrawal from Afghanistan. Gas prices soared; now they are coming down. Unemployment is at record lows, even as there are signs of a looming recession.

The president’s brand of politics is rooted in a slower era, before Twitter, and sometimes it can pay off to have the patience to wait for a deal to finally emerge. But now, with congressional elections coming up in a few months, the challenge for Biden is to make sure his latest successes resonate with Americans who remain deeply skeptical about the future.

Republicans moved quickly to attack the proposal, with Sen. Mitch McConnell, R-Ky., the Republican leader, deriding what he described as “giant tax hikes that will hammer workers.”

If Congress manages to pass the compromise reached with Manchin, they argue, it will move the country to the forefront on addressing the world’s changing climate and lower drug prices.

The deal would give Medicare the power to negotiate lower prices for millions of Americans, extend health care subsidies under the Affordable Care Act for three years and require corporations to pay a minimum tax — something many progressive Democrats have been demanding for years.

For Biden, that kind of success cannot come soon enough.

The elections this fall will determine which party controls the House and the Senate, with many experts predicting a Democratic drubbing. And doubts about the president’s own future are rising as fast as his popularity is sinking. A New York Times/Siena College poll conducted in early July found that 64% of Democrats wanted someone other than Biden to be the party’s nominee in 2024. A CNN poll later in the month put that figure at 75% among Democratic and Democratic-leaning voters.

Even as Biden hailed the news of the Senate deal Thursday, his own comments underscored the darker reality that he and his administration still face — a litany of promises that remain unfulfilled, with little evidence that more surprise victories are on the horizon.

During his remarks, the president himself listed many of the parts of his 2020 campaign agenda that remain stalled: more affordable child care, help for the elderly and those who care for them, cheaper preschool, efforts to confront the cost of housing, student debt relief and tuition-free community college, and money to cover health care for the poor in states that have refused to expand Medicaid.

The president’s failure to make good on those promises has left many people who were once his most ardent supporters disappointed, angry and — in some cases — even ready to abandon him.